At present, more and more people start to use a touch mobile phone, and a large screen and touch operations of the touch mobile phone are very popular among people. However, as the touch mobile phone is operated by touching, when a user calls, the face approaches the touchscreen of the mobile phone, which may cause a false trigger of the mobile phone. Therefore, an IR (infrared) proximity sensor is usually installed in the mobile phone. When the infrared proximity sensor detects that the light is blocked, the mobile phone considers that the face approaches the touchscreen, and therefore turns off the touchscreen, so as to prevent the false trigger caused by the approached face, and power can be saved during a call.
The infrared proximity sensor in the mobile phone can measure a reflected infrared ray intensity. Most of mobile phone manufacturers set a sensing threshold for an infrared proximity sensor, where the sensing threshold is used to determine whether the infrared proximity sensor is blocked, so as to determine whether the light above a touchscreen of a mobile phone is blocked, and finally determine whether the face of a user approaches the touchscreen of the mobile phone. Specifically, the sensing threshold of the infrared proximity sensor may be in a form of a value range (x, y), where x<y, when a reflected infrared ray intensity obtained by the infrared proximity sensor is greater than the upper limit value y of the value range (namely, y is the lower limit value at which the light of the infrared proximity sensor is blocked), it is determined that the light is blocked, and the touchscreen is turned off, and when the reflected infrared ray intensity obtained by the infrared proximity sensor is smaller than the lower limit value x of the value range (namely, x is the upper limit value at which blocking of the light of the infrared proximity sensor is canceled), it is determined that blocking of the light is canceled, and the touchscreen is turned on. In this way, because x<y, a problem that the touchscreen is frequently turned on and off due to fluctuation of an infrared ray intensity. Certainly, in actual use, the sensing threshold may also be in a form of a single threshold Z, when a reflected infrared ray intensity value obtained by the infrared proximity sensor is greater than Z, it is determined that the light is blocked, so the touchscreen is turned off, when the reflected infrared ray intensity value obtained by the infrared proximity sensor is smaller than Z, it is determined that blocking of the light is canceled, so the touchscreen is turned on, and when the reflected infrared ray intensity obtained by the infrared proximity sensor is just equal to Z, it may be set that the touchscreen is turned on or the touchscreen is turned off, which may specifically be preset in a system as required.
However, in the implementation of the present invention, the inventor finds that the prior art at least has the following problem.
Generally, an infrared proximity sensor is placed below a lens, where the lens is an extension part of a touchscreen of a mobile phone, and is generally made of a resin or glass material. The mobile phone has a certain requirement on the light transmittance of the lens. However, after the mobile phone is used for a long time, dust goes into the lens, or the surface of the lens is abraded or blotted, so that the light transmittance is affected, and the infrared proximity sensor is affected in receiving an infrared ray. When the light transmittance is reduced to a certain extent, in a case that the light is not blocked in a call, or actual blocking is canceled in the call, the mobile phone still considers that the mobile phone is blocked according to the sensing threshold and therefore turns off the touchscreen of the mobile phone, thereby affecting use of the mobile phone.